Normal vision acuity is considered equal to one. However, it is important for the person not the limit. There are people with visual acuity at 1, 5 and 1 and 5. If they have reduced visual acuity, please consult your ophthalmologist.
Visual inspection, as a rule, should be carried out once a year. To do this, one comes to the office of an ophthalmologist. Have your eyes examined by means of tables Sivtseva (Snellen). It looks like this. On a sheet of paper printed letters of various sizes (can transfer image by projection). The uppermost letters - the largest. Most small letters are located at the bottom of the table. For inspection of the table is located at a distance from the test at least 4 meters. A man sits on a chair, closing his right eye and reads the finest line of those who is able to see. Then this procedure is carried out his left eye. If a person can read the very bottom line, its vision is equal to one. If prescribed glasses, visual acuity is tested with glasses. Testing is carried out under strictly certain light table.
You can also learn visually impaired or not, and at home. To do this, buy or printed from the Internet to check the table view. It is secured to the wall, preferably without windows. Conduct test will help a person with perfect vision that sees the lowest line. The test reads the finest lines that is able to see and checking notes errors. Of course, at home to determine -2 vision or 1, 5 is not possible, but you can find out whether it has deteriorated or worsened.
If found to fall in visual acuity, should refer to the ophthalmologist. Medical practice and prescribe treatment, prescribe glasses or contact lenses.